What components of blood are central to blood volume setting in the kidney?
sodium, water
Formed elements (RBCs, WBCs, plasma) do not contribute directly to blood pressure.
Three ways to increase blood pressure?
high blood volume
vasoconstriction
high cardiac output
Fluid entering all Bowman's capsules?
Glomerular Filtration Rate
Diagnostic tests for kidney function?
Blood urea nitrogen (BUN)
Serum creatinine
B-type natriuretic peptide (BNP)
Which test measures urea, waste product of protein digestion, produced by the liver, and hence measuring if it is removed correctly by the kidneys?
blood urea nitrogen (BUN)
What is high BUN caused by?
low GFR
Along with low GFR, what can high BUN levels indicate?
kidney failure, CHF, hypovolaemia
What do high levels of serum creatinine indicate?
low GFR
Which hormone directly decreases diuresis?
Antidiuretichormone (ADH, vasopressin)
What is ADH secreted from?
posterior pituitary gland
Effect of decreased diuresis on blood pressure?
increased blood pressure
What is loss of plasma fluid into urine called?
diuresis
How do diuretic drugs work?
antagonise antidiuretic hormones, leading to fluid loss
Steroid hormone that increases plasma fluid?
aldosterone
What kind of hormone is aldosterone?
mineralocorticoid
What is aldosterone secreted by?
adrenal cortex
How does aldosterone increase plasma fluid?
aldosterone ➝ kidneys ➝ reabsorb more NaCl ➝ water follows salt ➝ reabsorb more water ➝ decrease diuresis by decreasing natriuresis
Hormone that increases blood pressure?
angiotensin II
How does angiotensin increase blood pressure?
causes vasoconstriction
increases fluid retention by:
increasing aldosterone secretion by adrenal cortex (more blood volume)
increasing ADH secretion by posterior pituitary (antidiuretic)
Hormone that contributes to ventricular hypertrophy + cardiac remodelling?
angiotensin II
What system regulates blood pressure and volume?
Renin-Angiotensin-Aldosterone System (RAAS)
Renin-Angiotensin-Aldosterone System mechanism?
angiotensinogen produced by liver ➝ activated by RENIN enzyme (made in kidneys) ➝ becomes angiotensin I ➝ activated by ACE enzyme (made in lungs) ➝ becomes angiotensin II ➝ activates aldosterone
Cytokine/hormone that derives erythropoiesis?
Erythropoietin (EPO)
Where is EPO made?
kidney
What is EPO made in the liver in response to?
hypoxia in kidney
What peptide hormone reduces fluid overload?
B-type Natriuretic Peptide (BNP)
What is B-type Natriuretic Peptide (BNP) secreted by?
ventricularcardiomyocytes
What is B-type Natriuretic Peptide (BNP) secreted in response to?
increased preload (diastolic stretching) and volume overload
How does B-type Natriuretic Peptide (BNP) work?
increases natriuresis ➝ increased GFR ➝ increase diuresis ➝ decrease venous pressure and systemic peripheral vascular resistance
Elevated levels of which hormone indicates heart failure?
B-type Natriuretic Peptide (BNP)
What does congestion inside hepatic portal system cause?
ascites
Fluid build up in abdomen?
ascites
2 ways kidney acid-base balance fails?
kidney failure (glomerulus doesn't filter)
renal tubular failure (tubules don't get rid of acid)
Low GFR, high creatinine & BUN, metabolic acidosis, high anion gap, high BP, low urine, oedema, need to urinate more esp at night?
Acute kidney injury / uremic kidney failure
Normal GFR, metabolic acidosis, normal anion gap, low blood K+, non-anion gap hyperchloremic metabolic acidosis?
Renal tubule failure
Example of thiazide like diuretic?
indapamide
Type of diuretics that work by blocking reabsorption at DCT?
thiazide like
Type of diuretics that work by blocking reabsorption in thick loop?